Dialog has rounded corners but not transparent edges

Question

I've got the dialog below that shows up on my app... As you can see I have the rounded corners i want but i want to remove the black for transparent edges.

Here is the style xml and image of the dialog:

<?xml version="1.0" encoding="utf-8"?>
<inset xmlns:android="http://schemas.android.com/apk/res/android" android:insetBottom="-1dp">
    <shape android:shape="rectangle">
        <solid android:color="@color/base" />
        <corners android:topLeftRadius="20dp" 
            android:topRightRadius="20dp"
            android:bottomRightRadius="20dp"
            android:bottomLeftRadius="20dp" />
        <stroke android:color="#7F7F7F" 
                android:width="1dp" />
    </shape>
</inset>

Answer 1

Try using

dialog.getWindow().setBackgroundDrawable(new ColorDrawable(0));

Answer 2

Or even simpler if you already use a custom theme for your dialog. Like below (only the necessary item is shown):

 <style name="NoBlackDefaultBackground" parent="@android:style/android:Theme">
    <item name="android:windowBackground">@drawable/transparent_background</item>       
</style>

Where you create a a custom 9 patch transparent_background.png